On the map i'm working on, it's quite difficult to make all the lighting look authentic. I've fixed all of the objects on the map so they work with the lighting, however the ground remains the same, regardless. Is there some way I can light the terrain so that it is affected by spot lights? Example, if I have a blue light pointing to the terrain, then the blue light should show on the ground.

Could you just color the terrain where the spotlight hits?

I was abou to suggst the same.

What I would do is place light in each area you want to affect the terrain with. Next, burn terrain. Finally (if the lights have messed up how your objects look) delete the lights again.

Well.. the only problem is I need the terrain to change ingame according to lighting. Coloring/burning will not work in this case. Oh well.

Yeah, you're outta luck there. Objects are dynamic, but terrain isn't.